This invention relates to monitoring authorization for persons gaining access to elevators and floor landings of a building by means of an elevator.
For security purposes, it has been known to prevent elevator start-up in the event that an unauthorized passenger has entered the elevator. Typically, passengers carry portable devices which emit identification numbers (IDs) usually using RF or IR electromagnetic radiation. In commonly owned, copending U.S. patent application Ser. No. 09/111,355, filed Jun. 7, 1998, now abandoned an elevator system determines when a passenger has entered an elevator, other than the elevator assigned to respond to an automatically entered, destination call. However, no prior systems determine if a passenger, generally authorized to use the elevator, nonetheless exits on a floor for which the passenger is not authorized, or if a passenger without a portable device may be impermissibly on an elevator.
Objects of the invention include determining when a passenger, not authorized to do so, attempts to ride an elevator during a restricted trip, or exits an elevator onto a secure floor landing; and determining when passengers without IDs are on or exiting an elevator.
According to the present invention, directional motion detectors at the entrance to each elevator on a secure floor of a building, when an elevator is present with its doors open, count the number of passengers who enter and leave the elevator, to maintain a current passenger count; a poll of passengers wearing portable, ID-emitting devices, determines whether unknown passengers and which particular known passengers are in the elevator, by default determining if unauthorized passengers have left the elevator at a secure floor; a comparison of exiting passenger ID numbers with authorized passenger ID numbers will set an alarm if unauthorized or unknown persons have left the elevator at a secure floor, the doors on the floor may be locked, security personnel notified, and/or an alarm condition set, or sounded.
In further accord with the invention, passengers boarding and exiting an elevator are counted; a count of IDs sensed indicates if passengers without IDs are on board and IDs are compared with authorizations on secure elevator trips to restrict elevator passengers to those authorized for a particular, secure trip; otherwise the car is disabled.
In one embodiment, motion detectors on either side of the hoistway door entrance and on either side of the elevator door entrance determine the direction of passenger movement differentially, depending on which devices sense motion first. In a second embodiment of the invention, doppler motion detectors (of the type used in stores to prevent exiting through automatic entrance doors) determines the direction of passenger movement.
Other objects, features and advantages of the present invention will become more apparent in the light of the following detailed description of exemplary embodiments thereof, as illustrated in the accompanying drawing.